ie6 img width:auto doesn't work

Question

I have an image element which is dynamically changed, and if necessary dynamically re-sized to fit its container.

My current process is:

1. reset image:

   // make sure the 'load' event is re-triggered
   img.src = "";
   // reset dimensions
   img.style.width = "auto";
   img.style.height = "auto";
   

2. set its new source and wait for it to load

   img.src = newImageSource;
   

3. in the images onload handler, the size is tested and if necessary, altered:

   img.style.width = newWidth + "px";
   

this is repeated as often as the image is changed (infinite).

This works fine for all browsers tested (ie7,8,9,10, FF, chrome) however ie6 setting width/height to "auto" seems to resize the element to around 25 x 25 px regardless of the actual image's dimensions.

So; is there a way to reset the images dimensions to the equivalent of "auto" so that the dimensions of the image subsequently loaded determines the elements dimensions for ie6?

Answer 1

I believe you can write

img.style.width = "";

to set the width to its default value of auto. Apparently img.style.width = "auto"; doesn't work the same way.